Electro-optical sensors, such as Mach-Zehnder interferometers, have been proposed as voltage sensors in the past. The linear voltage dynamic range of these devices, however, is limited to a fraction of a pi-voltage of the electro-optical sensor. If a device under test (DUT) is operated in this linear voltage dynamic range, then the available voltage dynamic range is determined by a signal-to-noise ratio at a receiver of the electro-optical sensor.